The present invention relates to a hybrid truss and a system of fabricating with the hybrid truss and more particularly to a hybrid truss with sleeves or pockets that receive the top of wooden posts or columns. The truss of this invention provides a means of very quickly fabricating or constructing a building that covers large spans with high overhead clearance.
Generally there are two basic methods of constructing a building, post and beam, and frame. These methods generally referred to the construction of the supporting structure for the outer sides of the building. Roof structure are generally referred to as either trusses or rafters, again depending on the type of construction. Trusses are typically engineered to be supported at the ends by the structure of the outer wall frame. Trusses generally span the distance between the walls without any interior support. Rafters, on the other hand, have a center support along the roof of the building""s centerline. Lumber is extended between the center support and the outer walls. Since rafters have a center support, rafters are not generally used where center openings and high overhead clearances are needed or desired.
Most building construction use trusses in one form or another for the roof. Several reason account for the wide use of trusses. Trusses are typically pre-made, so they do not have to be made at the site. This results in more uniformity in the roof structure and generally higher quality roof. Trusses can generally be placed a lot faster than rafters can be built. So the use of trusses speeds the construction of the roof. The use of trusses can also provide buildings with large center openings without center support.
There are a number of different designs and applications for trusses. This invention is directed to buildings generally classified as post and beam construction, at least as far as the primary support is concerned. However, the hybrid truss could be used in other types of construction as long as there are appropriate provisions for receiving the hybrid truss.
Generally, in post and beam type of construction vertical posts or columns are used as the primary supporting structure. Horizontal beams cross the posts to provide horizontal structure and stability, and for attachment of the wall covering. A horizontal beam is usually used at the top of the post for attaching the trusses or rafters. As such, the top of all the posts most be horizontally leveled before the attachment of the top beam or top plate, as it may be called. The ends of the trusses or rafters typically are positioned on and rests upon the top plate or top beam. It takes a considerable amount of time in most post and beam construction to level the top of the posts. This is due to the leveling of the grounds and foundation, and the building of a wall having a uniform height placed on the leveled foundation. Or if posts are used without a foundation, the tops all have to be leveled. Using the hybrid truss of this invention eliminates the need to level the top of the posts and eliminates the need for the truss to rest upon the top plate or top beam. This saves a considerable amount of time and material. The ground upon which the building is built does not need to be leveled nor does a level foundation need to be built.
Trusses are typically engineered to place the weight of the truss in a downward force on the side walls. In order to do so, there is generally a horizontal cross member to absorb the outward forced created by the weight on the peak of the roof. Trusses with a horizontal cross member eliminates the capability of having high overhead clearance without having high walls. In order to overcome this disadvantage, scissor trusses were created. Scissor trusses have the capability of creating higher center clearances, but generally cannot be used to span very large distances. Scissor trusses generally use a pair of cords which either are parallel to each other, one above the other with bracing between, or, most commonly, have a pair of cords with a greater distance between the two cords at the peak, than at the lower end. Scissor trusses also rest on the top plate or top beam of the walls. But, scissor trusses can also create an outward force on the walls. The lower cords of scissor trusses are designed to minimize the outward force by directing the force to a tension or pulling force at the junction of the lower cords at the peak. When weight of the roof sheeting and roofing material is added this force can become very high. Many scissor trusses fail at this junction.
The hybrid truss of this design uses a sleeve that is rigidly attached to one or two cords, and cross bracing on the truss. The sleeve is designed and attached to the truss to redirect forces of the cords to the post in a downward force and to reduce outward forces. The sleeves have an opening which receives the top of the posts. In this manner, the trusses are attached to the posts rather than being attached to the top plate or beam. In addition, the sleeve is constructed and attached to the overall truss structure in such a manner that the outward forces of the scissor trusses are greatly reduced and are redirected into a downward force on the posts. Since the truss of this design redirects the outward forces on the lower cords, larger spans are possible.
Accordingly, it is an object of the present invention to provide a hybrid truss, and a system of fabricating a building with the hybrid truss, adapted to save time and material during construction. With the hybrid truss and system of fabricating a building with a hybrid truss of this invention it has been found that the top plate or top beams do not have to be used and the tops of the posts do not have to be leveled. Since the sleeves receives the top of the posts, the hybrid trusses themselves are leveled rather than the top of the posts, or the top plate or beam. As a result, a considerable amount of time is saved.
Another object of the present invention is to provide a hybrid truss, and system of fabricating a building with the hybrid truss, constructed to provide buildings with a large center span with high overhead clearance. Since outward forces are redirected to the sleeve, larger spans with high overhead clearances are possible.
A further object of the present invention is to provide a hybrid truss, and a system of fabricating a building, with the hybrid truss adapted for quick and easy installation for saving time during construction. The sleeves receives the top of the posts and are attached to the posts. As such, the hybrid truss of this invention is simply lowered onto the posts, with the sleeves receiving the top of the posts, and when the hybrid truss is properly positioned and leveled the sleeve is secured to the post. Thereby, substantially saving construction time.
Still another object of the present invention is to provide a hybrid truss, and system of fabrication a building with a hybrid truss, that may be easily hauled to the construction site but yet span large open areas with a high overhead clearance. The hybrid truss and system of fabrication a building with a hybrid truss of this invention is preferably made with symmetrical sections that can be joined at the peak at the construction site. As such, trusses that span large openings with high overhead clearance are provided that can be hauled by standard trucks without violating any road size restrictions.
Another object of the present invention is to provide a hybrid truss, and a system of fabricating a building with the hybrid truss, that allows the use of steel trusses with a steel sleeve to receive the top of a wooden post or column. Typically, in the past, metal trusses were used by attaching to steel posts, or attached to wooden top plates or top horizontal beams. These systems or methods needed a considerable amount of time for leveling and alignment. The hybrid truss, and system of fabricating a building with the hybrid truss, greatly reduces the amount of time needed in these steps. The steel sleeve is simply placed over the tops of properly placed wooden posts or columns. There is no need to level the top of the posts. The sleeve is simply positioned level with the other trusses and is secured to the post, thereby saving a considerable amount of time.
To accomplish the foregoing and other objects of this invention there is provided a hybrid truss and a system of fabricating a building with the hybrid truss.
The hybrid truss, and a system of fabricating a building with a hybrid truss of this invention, provides a truss that can span large widths without a center support to create an open area having high overhead clearance and a system of fabricating or constructing a building using the hybrid truss. Each hybrid truss is made with two symmetrical members, or truss members, that join at the peak. Each member is made with two cords, which are parallel in the preferred embodiment, but can be nonparallel in some instances. The cords have cross bracing between two cords, and have a peak end member. The peak end members are used to join two truss members at a peak to form the entire hybrid truss. Attached at the lower end of each member of the truss is a unique sleeve. The sleeve is rigidly attached to the truss cords and bracing. The sleeve is designed to slide over the top of a post or column. The sleeve is used to attach and properly position the truss on the top of the posts or columns. In preparation to receive the hybrid truss, the posts are simply properly-placed, and cut to a general height. They do not need to be level across the top. The hybrid trusses are simply lifted and placed on the posts with the sleeve fitting over the top of the posts. The sleeve is then secured to the post with bolts, screws or other fasteners, once the truss is properly positioned height-wise. Backing 2xc3x974""s or 2xc3x976""s are attached across the top cord of the trusses and to the outside of the posts. Roofing and wall covering are installed on the backing.
In the preferred embodiment, the posts are wooden posts or timbers. These are embedded to a proper depth, depending on the soil conditions and loading factors of the building. Once the wooden posts are all positioned and generally cut to a height, the trusses can be properly positioned and secured to the tops of the wooden posts. A unique factor is the use of the steel sleeve on the hybrid truss and the positioning and securing the truss on wooden posts. There is no known system having this combination.
The above mentioned and other objects, and features of the present invention will be better understood and appreciated from the following detailed description of the main embodiment thereof, selected for purposes of illustration and shown in the accompanying drawings.